body {
    font-family: Arial;
    text-align: center;
    background: #f5f5f5;
}

h1 {
    color: #333;
}

.input-section input {
    margin: 5px;
    padding: 8px;
}

button {
    padding: 8px 12px;
    margin: 5px;
    cursor: pointer;
}

table {
    margin: 20px auto;
    background: white;
}

#output {
    margin-top: 20px;
    font-weight: bold;
}

#gantt {
    display: flex;
    justify-content: center;
    margin-top: 20px;
}

.box {
    padding: 10px;
    border: 1px solid black;
    margin: 2px;
    background: lightblue;
}

/* ACTIVE BUTTON */
.active-btn {
    background-color: #4CAF50;
    color: white;
}